cpp: Validate the transition map
* lang/cpp/src/gpgsignkeyeditinteractor.cpp (makeTable): Assert that all transitions go from one state to a different state.
The state machine gets stuck if a transition doesn't change the state.
Make sure that this cannot happen again by mistake.
Taken from gpgmepp commit 6f2e91d4d25afa6934ceaf1563a4d826a904d644
- GnuPG-bug-id: T7600